- Development of the fins in the vampire is unique among cephalopods. One pair is present at hatching and is eventually resorbed and replaced by a more anterior pair as development proceeds. At one stage in development, therefore, the vampire has two pairs of fins. The first pair to develop is the homologue of the fins of other cephalopods (Young and Vecchione, 1996). The unusual fin ontogeny is partially responsible for the early description of 3 families and many species where only one species actually exists. Except for the fins, the young vampire squid (ca 10 mm ML) have an appearance very similar to that of the adult.
- Eggs and hatchlings
- Vampires lack nidamental glands and have rather small oviducal glands. As a result there is little likelihood that they produce large egg masses. Off California small vampire squid occupy greater depths than do the larger individuals (Roper and Young, 1975) suggesting that spawning occurs in very deep water. A hatchling is known from deep water off Hawaii.